Longitudinal double-spin asymmetry for inclusive jet and dijet production in polarized proton collisions at √(s)=200 GeV

2021/03/31 by STAR Collaboration, M. S. Abdallah, J. Adam +378 · 1 citation
Physics and Astronomy · #hep-ex #nucl-ex

paper · pdf · doi:10.1103/physrevd.103.l091103

published as Phys. Rev. D 103, 091103 (2021) · 14 pages, 4 figures

arxiv created 2021/05/28 · arxiv updated 2021/06/02

Abstract

We report high-precision measurements of the longitudinal double-spin asymmetry, A_LL, for midrapidity inclusive jet and dijet production in polarized pp collisions at a center-of-mass energy of √(s)=200 GeV. The new inclusive jet data are sensitive to the gluon helicity distribution, Δg(x,Q²), for gluon momentum fractions in the range from x ≃ 0.05 to x ≃ 0.5, while the new dijet data provide further constraints on the x dependence of Δg(x,Q²). The results are in good agreement with previous measurements at √(s)=200 GeV and with recent theoretical evaluations of prior world data. Our new results have better precision and thus strengthen the evidence that Δg(x,Q²) is positive for x > 0.05.

Cited by

• Weizsäcker-Williams Gluon Helicity Distribution and Inclusive Dijet Production in Longitudinally Polarized Electron-Proton Collisions